The parallels of Croom's time at MSU with Mike Shula's at Alabama are worth noting.
They both came in untested as Head Coaches, and with only moderate success as assistants. For different reasons, they both inherited teams with limited talent.
They both struggled for a couple of years, though Croom did have a few upsets that qualified as "signature" wins (goodness, I hope I never hear that term again), and Shula struggled on that front until 2005.
They both had what appeared at the time to be a breakout year -- Shula in 2005 and Croom in 2007. But in retrospect, both years were times in which every conceivable break went their way. In other words, they got lucky. Odds caught up with both in the following year, and it got ugly, especially as the season wore on.
Like Shula, it appears that Croom will be given an ultimatum: make meaningful change, especially on offense, or else. I think Croom learned enough from watching Shula -- and make no mistake, Sylvester Croom watches every move Alabama makes as closely as any Aub -- not to repeat Shula's proposal that barely even qualified as window dressing.
So I think Croom will clean house offensively, but that it won't help. Any new OC has to know the talent level is abysmal and the odds are stacked against a team that plays Alabama, Auburn, LSU, and Arkansas every year, and has a resurgent Ole Miss as the in-state rival. Bringing a new offense into that buzzsaw, with little talent to run it, almost certainly cannot succeed.
If Croom proposes change, MSU will be on the job market in 365 days. If he doesn't, it'll be less than two weeks.